Human thyroid functions at risk in exposure to fracking fluids
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By Summit Voice
FRISCO — Exposure to the semi-secret brew of chemicals used for fracking blocks hormone receptors and interferes with other other functions that regulate basic body chemistry, scientists said this week, announcing the results of a study that identifies specific health outcomes related to the poisons.
Previous research has described the impact of endocrine-disrupting toxins to reproductive hormones. In the new study, the biologists found that fracking chemicals also disrupt glucocorticoid and thyroid hormone receptors.
“Among the chemicals that the fracking industry has reported using most often, all 24 that we have tested block the activity of one or more important hormone receptors,” said Christopher Kassotis, a PhD student at the University of Missouri, Columbia. “The high levels of hormone disruption by endocrine-disrupting chemicals that we measured, have been associated with many poor health outcomes, such as infertility, cancer and birth defects.”
Kassotis presented the study findings this week at the joint meeting of the International Society of Endocrinology and the Endocrine Society: ICE/ENDO 2014 in Chicago.
Hydraulic fracturing is the process of injecting numerous chemicals and millions of gallons of water deep underground under high pressure to fracture hard rock and release trapped natural gas and oil. Kassotis said spills of wastewater could contaminate surface and ground water.
Working in Garfield County, Colorado, the same research group previously found moderate to high levels of EDC activity that mimicked or blocked the effects of the female hormones (estrogens) and the male hormones (androgens) in human cells.
The new findings ominously reinforces science showing that high-use fracking chemicals mess with the human body at a molecular level, preventing hormones from binding with cells.
The new study extended the analysis to learn whether high-use fracking chemicals changed other key hormone receptors besides the estrogen and androgen receptors. (Receptors are proteins in cells that the hormone binds to in order to perform its function.) Specifically, the researchers look for an affect on thyroid function, which helps control metabolism, normal brain development and other functions needed for good health.
Among 24 common fracking chemicals that Kassotis and his colleagues repeatedly tested for EDC activity in human cells, 20 blocked the estrogen receptor, preventing estrogen from binding to the receptor and being able to have its natural biological response, he reported. In addition, 17 chemicals inhibited the androgen receptor, 10 hindered the progesterone receptor, 10 blocked the glucocorticoid receptor and 7 inhibited the thyroid hormone receptor.
“We don’t know what the adverse health consequences might be in humans and animals exposed to these chemicals,” Kassotis said, “but infants and children would be most vulnerable because they are smaller, and infants lack the ability to break down these chemicals.”